Diabetes mellitus comprises a cluster of diseases distinguished by chronic hyperglycemia that result from the body's failure to produce and/or use insulin, a hormone produced by β-cells in the pancreas that plays a vital role in metabolism. Symptoms include increased thirst and urination, hunger, weight loss, chronic infections, slow wound healing, fatigue, and blurred vision. Often, however, symptoms are not severe, not recognized, or are absent. Diabetes can lead to debilitating and life-threatening complications including retinopathy leading to blindness, memory loss, nephropathy that may lead to renal failure, cardiovascular disease, neuropathy, autonomic dysfunction, and limb amputation. Several pathogenic processes are involved in the development of Diabetes, including but not limited to, processes which destroy the insulin-secreting β-cells with consequent insulin deficiency, and changes in liver and smooth muscle cells that result in resistance to insulin uptake. Diabetes can also comprise abnormalities of carbohydrate, fat, and protein metabolism attributed to the deficient action of insulin on target tissues resulting from insulin insensitivity or lack of insulin.
Type 2 Diabetes is the most common form of Diabetes, which typically develops as a result of a relative, rather than absolute, insulin deficiency, in combination with the body's failure to use insulin properly (also known in the art as “insulin resistance”). Type 2 Diabetes often manifests in persons, including children, who are overweight; other risk factors include high cholesterol, high blood pressure, ethnicity, and genetic factors, such as a family history of Diabetes. The majority of patients with Type 2 Diabetes are obese, and obesity itself may cause or aggravate insulin resistance. Apart from adults, an increasing number of children are also being diagnosed with Type 2 Diabetes. Due to the progressive nature of the disease, Diabetes complications often develop by the time these children become adults. A study by the American Diabetes Association (ADA) involved 51 children that were diagnosed with Diabetes before the age of 17. By the time these children reached their early 30s, three had kidney failure, one was blind, and two died of heart attacks while on dialysis. This study reinforces the severity of the disease, the serious damage inflicted by Diabetes complications, and the need for early diagnosis of the disease.
The incidence of Diabetes has been rapidly escalating to alarming numbers: Diabetes currently affects approximately 170 million people worldwide with the World Health Organization (WHO) predicting 300 million diabetics by 2025. The United States alone has 20.8 million people suffering from Diabetes (approximately 6% of population and the 6th most common cause of death). The annual direct healthcare costs of Diabetes worldwide for people in the 20-79 age bracket are estimated at $153-286 billion and is expected to rise to $213-396 billion in 2025.
Along with the expansion of the diagnosed diabetic population, the undiagnosed diabetic population has also continued to increase, primarily because Type 2 Diabetes is often asymptomatic in its early stages, or the hyperglycemia is often not severe enough to provoke noticeable symptoms of Diabetes. It is believed that approximately 33% of the 20.8 million diabetics in the United States remain undiagnosed. Due to the delay in diagnosis, Diabetes complications have already advanced and thus, the future risk of further complication and derailment is severely increased. To obviate complications and irreversible damage to multiple organs, Diabetes management guidelines advocate initiation of therapeutic intervention early in the prognosis of the disease.
This modern epidemic requires new tools for early detection of Type 2 Diabetes, before the disease instigates significant and irreparable damage. In addition, new treatment paradigms are needed to halt, delay, or ameliorate the massive deterioration in patient health, ideally reversing the course of the disease to partial or complete cure as an alternative or a substitute for current treatments, which merely address chronic management of disease symptoms. Diabetic hyperglycemia can be decreased by weight reduction, increased physical activity, and/or therapeutic treatment modalities. Several biological mechanisms are associated with hyperglycemia, such as insulin resistance, insulin secretion, and gluconeogenesis, and there are several agents available that act on one or more of these mechanisms; such as but not limited to metformin, acarbose, and rosiglitazone.
It is well documented that the pre-diabetic state can be present for ten or more years before the detection of glycemic disorders like Diabetes. Treatment of pre-diabetics with therapeutic agents can postpone or prevent Diabetes; yet few pre-diabetics are identified and treated. Thus, there remains a need in the art for methods of identifying and diagnosing these individuals who are not yet diabetics, but who are at significant risk of developing Diabetes. There is also no known preventative measure which can be taken against Type 1 diabetes.
Type 1 diabetes (“T1D”), or insulin-dependent diabetes mellitus (“IDDM”) is an autoimmune disease associated with the selective destruction of pancreatic β-cells and chronic insulin deficiency that affects 1 in 300 people in the U.S. Studies of humans with T1D and non-obese diabetic (NOD) mice (an animal model for T1D) indicate that T1D is a T-cell mediated inflammatory disease. In mice, lymphocytic infiltration surrounding the islet cells, termed insulitis, is the initial pathological finding, occurring at 5-8 weeks. These infiltrates contain many types of inflammatory cells including antigen-presenting cells (e.g., macrophages), T-helper cells, cytotoxic T-cell, B-lymphocytes and natural killer cells (Paintlia et al., J Neuro Sci Res. 77:63-81, 2004; Donath et al., J Mol Med. 81:455-470, 2003; Durinovic-Bello et al., Ann NY Acad Sci. 1005:288-94, 2003; Herold K C, Endocrinol Metab Clin North Am. 33(1):93-111, 2004; Faresjo et al., Scand. J Immunol. 59:517-26, 2004; Gottlieb and Hayward, Endocrinol Metab Clin North Am. 31(1):477-95, 2002; Roep B O, Diabetologia 46(3): 305-21, 2003; Matteucci et al., Clin Exp Immune 136:549-554, 2004).
Since Type 1 diabetes is due to the destruction of pancreatic β-cells, pancreas-kidney transplantation or exogenous transplantation with blood cells in Type 1 diabetic patients are treatment options. However, these treatments require long-term immunosuppressive drug therapy. Thus, there is a need in the art for improved treatments and preventative measures for Type 1 diabetes.